Introduction

Overview of HIV/AIDS

Human immunodeficiency virus (HIV) and its complications have claimed the lives of about 630,000 people, with about 1.3 million newly diagnosed cases in 2023. Towards the end of 2023, an estimated 39.9 million people were living with HIV infection within Africa accounting for 65% of cases. HIV infects humans by attacking their immune system and destroying white blood cells called CD4 cells leaving them defenseless against other infections like bacteria pneumonia, toxoplasmosis, cancer, etc. HIV can be transmitted through body fluids of an infected individual such as breastmilk, blood, semen, and vaginal fluids. Acquired immunodeficiency syndrome (AIDS) is the clinical manifestation of the later stages of HIV infections which is defined by WHO as CD4 cell counts less than 200 cells/mm3.¹ Symptoms are initially flu-like, and later specific to a weakened immune system. 

Flu-like symptoms include

• Sore throat
• Fever and chills
• Body rash 
• Headache
• Muscle aches

Specific symptoms due to a weakened immune system include enlarged lymph nodes, cough, diarrhoea, weight loss, night sweats as well as fever.¹

Overview of bacterial pneumonia

An estimated 15% of deaths of children under 5 years in 2017 were caused by pneumonia killing over 808,000 children in 2017. Bacterial pneumonia is an infection of the lower respiratory tract notably bronchioles and alveoli by a bacteria. Vulnerable populations include children, elderly and immunosuppressed populations. 

Bacterial pneumonia is classified into two kinds depending on the place of infection, community-acquired pneumonia (CAP) and Nosocomial pneumonia. CAP is diagnosed in patients who are either not hospitalised or within 48 hours of admission in previously non-hospitalised patients.² 

CAP is subdivided depending on the type of bacteria into: 

• Typical pneumonia caused by bacteria like Klebsiella pneumoniae, Streptococcus pneumoniae, Haemophilus influenzae, Staphylococcus aureus, Group A Streptococcus, Moraxella catarrhalis, anaerobes, and gram-negative organisms
• Atypical pneumonia is caused by Legionella pneumophila, Chlamydia pneumonia, and Mycoplasma pneumonia²

Nosocomial pneumonia which is pneumonia diagnosed in hospitalised patients is classified into:

• Hospital-acquired pneumonia
• Healthcare-associated pneumonia
• Ventilator-associated pneumonia²

Bacterial pneumonia in HIV/AIDS patients

In persons living with HIV (PLHIV), there is a suppressed immune system which leaves the individuals defenceless against opportunistic infections from microorganisms, amongst which bacteria is included. These bacteria pneumonia in PLHIV is usually caused by: 

• Mycobacterium tuberculosis
• Streptococcus pneumonia
• Haemophilus
• Pseudomonas aeruginosa 
• Other mycobacterium species³ 

Bacterial pneumonia is more frequent in PLHIV than in HIV seronegative individuals, and its risk increases with reduced CD4 count.⁴

High-risk populations

All HIV-infected persons with CD4 cell count < 200 cells/mm³ are at risk of bacteria opportunistic infections. Goldin and collaborators demonstrated that the following have increased the risk of bacterial infection in:

• PLHIV who smoke cigarettes
• HIV-infected persons who are either not on treatment or aren’t consistent with their treatment plan ⁵

Morbidity and mortality rates

Bacteria pneumonia in PLHIV has been associated with high morbidity and mortality rates as shown by Sogaard and collaborators in 2009.⁶

Clinical manifestations 

Symptoms of bacteria pneumonia in HIV/AIDS Patients

HIV-associated bacteria pneumonia clinically presents with the following symptoms:

• Acute onset of fever
• Chills
• Cough which produces purulent sputum
• Chest pain
• Difficulty in breathing
• Shortness of breath
• Elevated white blood cell counts
• Inspirational crackles during auscultation
• Signs of consolidation and sometimes pleural effusion.^1,3

Challenges in differentiating bacterial pneumonia from other lung infections

Differentiating between HIV-associated bacterial pneumonia and other opportunistic pneumonia is difficult clinically as clinical manifestations are similar. These opportunistic pneumonia include

• Pneumocystis pneumonia (PCP)
• Cryptococcus neoformans pneumonia
• Toxoplasma gondii pneumonia
• Other Fungal pneumonia ³

Diagnosis

Diagnosis of HIV-associated pneumonia is carried out using the following tools

• Chest X-ray or CT scan
• Sputum culture 
• Blood cultures 
• Bronchoscopy ³ 

Treatment and management

Antibiotic therapy

Treatment of bacterial pneumonia in HIV-infected persons is done by administering the appropriate antibiotic medication similar to HIV-negative individuals. Depending on the causal bacteria, the following antibiotic class combination can be used

• Beta-lactam + macrolids
• Fluoroquinolones or doxycycline in cases of allergies to the previous combination
• Fluoroquinolones are strongly encouraged in cases of confirmed mycobacterium tuberculosis.³

Role of antiretroviral therapy (ART)

Antiretroviral therapy is not a cure for HIV, but a means to suppress the virus and improve immunity. This combined ART reduces the risk of opportunistic infections, bacteria infection inclusive, and HIV-associated cancers. Antiretroviral medications should be taken by the patient every day throughout life.³

Prevention

Vaccination strategies

Pneumococcal vaccines:

• 13-valent protein-conjugated pneumococcal polysaccharide vaccine (PCV13) 
• 23-valent pneumococcal polysaccharide vaccine (PPV23) 

These are used as preventive measures for bacteria pneumonia in PLHIV. A recommended dose of PCV13 for all PLHIV followed by PPV23 at least 12 months later.³     

Administration of pneumococcal vaccines has been proven to reduce trends of bacterial pneumonia in HIV-infected individuals.⁷

Prophylactic antibiotics

Trimethoprim-sulfamethoxazole also known as cotrimoxazole used in prophylaxis for pneumocystis pneumonia has been shown to decrease the frequency of bacteria pneumonia in HIV-infected individuals.³ 

Bacteria pneumonia caused by mycobacteria tuberculosis is prevented by administering Isoniazid daily or twice weekly for 9 months.³ 

Early detection and regular monitoring

Early detection of bacterial pneumonia in PLHIV through routine checkups has reduced the mortality rate of opportunistic infections in HIV-infected persons. Multiple programs and guidelines have been put in place to ensure early detection and management. 

When do I see a doctor?

Every PLHIV has to see the doctor routinely for disease follow-up and management. You should also visit the doctor if you observe any of the following symptoms

• Cough
• Fever
• Chest pain
• Shortness of breath
• Sore throat

FAQs

Why do HIV patients get pneumonia?

HIV infects humans by attacking their immune system destroying white blood cells known as CD4 cells leaving them defenseless against other infections like bacteria pneumonia, toxoplasmosis, and cancer. The human immune system depends on the elevated CD4 cells which are destroyed by HIV. Bacteria that are common in communities like streptococcus, staphylococcus, and Haemophilus influenzae take the opportunity to infect these defenceless persons easily. With a low immune system to combat against this bacteria, the infection rapidly progresses to severe cases.

What is the most common respiratory infection in HIV patients?

Bacteria pneumonia is the most common lower respiratory tract infection in patients living with HIV. They are essentially caused by agents like Staphylococcus aureus, Streptococcus pneumonia, Pseudomonas species, Haemophilus influenzae and Klebsiella species.⁸

In Africa, the most common bacteria pneumonia in HIV-infected persons is Tuberculosis caused by the bacteria Mycobacterium tuberculosis.³   

How can bacterial pneumonia be prevented in HIV-infected persons?

Bacteria pneumonia can be prevented in the following way

• Strict adherence to antiretroviral therapy and prophylactic treatments according to your doctor’s prescription
• Avoid unhealthy habits like smoking cigarettes
• HIV-infected persons should avoid healthcare jobs requiring taking care of elderly people, as well as persons infected with tuberculosis or other bacteria infections⁵

Summary

Bacteria pneumonia is very common and can easily complicate the condition of people living with HIV (PLHIV),  leading to high mortality rates. HIV-infected patients can maintain or improve their immune system by strictly adhering to antiretroviral therapy thus preventing infection by opportunistic bacteria. Other preventive measures include prophylactic treatments, vaccinations, avoiding smoking cigarettes, and contact with bacteria-infected persons.